Cold embossable web



pril 23, i968 l. D. THARP 3,379,560

COLD EMBossABLE wBB Filed March 18. 1964 Tlc* 4.

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50.4025@ Fam, ,DP/m5@ .co/47; 24 INVENTOR ATTOR Y United States Patent O poration of Delaware Filed Mar. 18, 1964, Ser. No. 352,856 1 Claim. (Cl. 117-121) This invention relates to embossable webs and more especially it relates to such webs which are capable of being cold-embossed with desired indicia or designs.

A principal object of `the invention is to provide a novel combination of elements which constitute an improved cold-embossable web or strip.

Another object is to provide an embossable web or strip which can be embossed to produce any predetermined color contrast in the embossed areas with respect to the unembossed areas.

Another object is to provide a composite embossable web or strip which can be cold-embossed to produce therein any desired design and with a maximum of visual or color contrast between the embossed an-d the unembossed areas.

A feature of the invention relates to an embossable web comprising a cold-embossable backing of paper, cardboard, metal, plastic, or the like, having a plasticized film formed thereon and adherent lthereto with a predetermined `adherent force, but which when subjected to localized embossing pressure distorts the backing permanently to the desired indicia or design and at the same time causing the plasticized film to completely disrupt at the embossed regions so that at those regions it substantially completely reveals the permanent embossments of the backing.

Another feature relates to .an embossable web comprising a cold-embossable backing of material such as paper, cardboard, plastic, or the like to which is adherently attached a plasticized film capable of being completely ruptured only in the embossed 'areas whereby the color of the embossments on the backing is substantially completely visible through the said completely ruptured areas.

A further feature relates to a composite plastic web or strip including a plurality of layers, one of which is transparent or at least translucent and of a non-crazin'g plastic and forming an embossable backing to which is bonded a plasticized colored film. The adhesive bond between the film and backing is such that the plasticized film remains permanently adherently attached to the backing at the unembossed regions of the backing but is capable of selfcontraction at the embossed regions to form completely clear openings or windows through which the embossments of the backing project.

A further feature relates to a composite plastic web or strip including a plurality of layers, one of which is a colored plastic embossable backing to which is bonded a plasticized colored film of a contrasting color with the backing. The adhesive bond between the film and backing is such that the plasticized film remains permanently adherently attached to the backing at the unembossed regions of the backing but is capable of self-contraction at the embossed regions to form completely clear openings or windows through which the embossments of the backing project.

A still further feature relates to the novel organization, arrangement and relative location and composition of elements which cooperate to provide an improved embossable web or strip.

Other features and advantages not Specifically enumerated will be apparent after a consideration of the following detailed descriptions and the appended claim.

In the drawing, which shows by way of example certain prefered embodiments,

FIG. '1 is a highly magnified cross-sectional perspective view of a portion of a web or strip according to the invention',

FIG. 2 is a cross-sectional view of a portion of FIG. 1 showing an embossed region thereof and with the strippable backing of FIG. 1 removed;

FIG. 3 is a top plan view of FIG. 2;

FIG. 4 is a modification of FIG. 1;

FIG. 5 is another modification of FIG. l;

FIGS. 6 to 8 are respective schematic diagrams explanatory of the invention.

Referring more particularly to FIGS. 1-3, one product according to the invention comprises a plural-stratum assembly including a layer 10 of transparent or at least translucent material such as paper, fabric, plastic, or the like. The layer 10 should be of sufiicient thickness so that it retains its fiat or planar shape except when subjected to embossing pressure at localized areas. For example, it may be a sheet of any known clear plastic of 0.001 inch to 0.0018 inch thickness. This material constitutes the embossing base for the assembly.

Coated on to the upper surface of layer 10 is a stratum or layer 11 of a non-brittle film-forming plastic or other elastomer which is prepared so that it has a high order of elasticity up to a certain point and when subject to embossable pressure beyond that point it completely ruptures and contracts at the embossed region but without fragmentation.

In accordance with the invention layer 10 is such that when it is subjected to such localized dispersion as an embossment, it follows the shape of the embossing die until the material of layer 11 reaches its elastic limit. Thereupon it is completely disrupted without fragmentation at the embossing region to leave a completely open area or window at that region. The material of layer 11 at the disrupted region immediately contracts because of its high elasticity towards the margin of the opening. In other words, the layer 11 can be formed by .an embossing operation with clear openings or windows defining any desired indicia as determined by the shape of the embossing die. The remainder of layer 11 retains its planar or unembossed formation since it is adherently attached to the layer 10. The bond between the layer 11 .and the layer 10 should be such that when the layer 11 is disrupted beyond its elastic limit the component of force in the embossed region exceeds the adhesive force so as to enable ythe layer 11 at that region to completely contract as above mentioned.

The material of which the coated layer 11 is constituted may be any well known plasticized film-forming resin whether natural or synthetic, or any other well known elastomer of which rubber or latex films are typical. Preferably, although not necessarily, the layer 11 is prepared from any one of a number of such resins or elastomers, for example of the polyvinyl resin kind, vinyl chloride-vinyl acetate copolymers, vinylidine chloridevinyl acetate copolymers, vinylidine chloride polymers, styrene polymers and the like.

The invention is not limited to any particular manner of depositing the layer 11 on the layer 10 which may be effected by casting,.spraying, dipping or brush or knife coating. The layer 11 also has included during its formation a pigment such as powdered carbon or other colored powder, or it may include a coloring agent or dye, so that when dry the layer 11 is opaque or substantially so. Applied in any known manner to the opposite surface of layer 10 is any known colored adhesive 12, such for example as those prepared from the isobutylenes, rubber, butadienestyrenes, methacrylates, acrylates, -vinyls and the like. These polymeric materials having been plasticized, stabilized and tackified to provide tenacious adhesiveness of the embossed assembly to the desired surface. Strippably attached to the adhesive layer 12 is a paper, cardboard, plastic film or other removable backing 13. The surface of backing 13 is smooth on the side engaging the adhesive 12 so that while it forms a part of the complete assembly prior to embossing, it can be readily peeled from the assembly after embossing, leaving the layer 12 exA posed so that the embossed assembly, consisting of the layers 10, 11 and 12, as shown in FIG. 2, can be readily attached to any desired surface.

Typical formulations for the coating 11 are as follows:

Example I P.b.w. Polyvinyl chloride-acetate (VYNS, VYNW, etc.) 16.30

Coloring pigment (carbon black, etc.) 2.80 Stabilizer (lead carbonate) 0.13 Fatty acid ester (Acrawax) 0.65 Vinyl stabilizer (Nuostabe V-1089) 0.32 Methyl ethyl ketone 66.70 Methyl isobutyl ketone 13.10

Example II P.b.w. lPolyvinyl chloride-acetate (VYHH, VYNS, etc.) 3.65 Polyvinyl chloride (Geon 101) 3.65 Nitrile rubber (Paracril CV) 0.35 Coloring pigment (iron oxide, carbon black, etc.) 9.15 Vinyl stabilizer (Nuostabe V-1089) 0.20 Stabilizer (lead carbonate) 0.10 Vinyl stabilizer (Victor #53) 0.45 Methyl ethyl ketone 68.60 Methyl isobutyl ketone 13.85

The above ingredients of either example are mixed to form a dispersion which can be ball-milled or otherwise agitated for a sufficient time to homogeneously distribute the powdered coloring ingredient throughout the dispersion. This fluid dispersion is then coated to a dry film thickness of from about 0.0005 to 0.001 inch on to the transparent or opaque sheet or 22, which sheet is of the non-crazing type represented by Mylar, poly carbonate, cellulose acetate. The non-crazing film may have a thickness of from about 0.003 to 0.020 inch. After the coating 11 has been dried, the adhesive coating 12, for example of polyisobutylene suitably stabilized, plasticized, tackified and with or without fillers and coloring matter can be applied and then attached to the strippable backing 13 which may be of extensible paper products, fabric or plastic films capable of suicient stretch to withstand embossing operations and which have been so treated to afford their relatively easy separation from the adhesive layer 12 as desiredat the point of use. Examples of extensible paper products are those represented by the trade names Clupak, Expanda, etc, Stretchable films such as polyethylene and/ or polypropylene can similarly be employed.

The invention is not limited to any particular mechanism for effecting the embossment of the laminated assembly of FIG. 1. Preferably the embossing device is of the hand-operated kind and reference may be had to U,S. Patent 2,275,670 for that purpose. A typical embossing dye is represented schematically in FIG. 8 by the male die member 14 and the cooperating female die member 1S. Preferably a compressible member 16 is provided between the opposed fiat faces of the die members so that when the laminated assembly of FIG. 1 is clamped between the die members with the backing sheet 13 in contact with the die member 14, and the die members are moved towards each other, the embossing portion 17 distorts the laminated assembly. Preferably the depth of the recess 18 in the die member 1S is such that it permits the assembly to be embossed to its desired height but still leaves a slight clearance between the layer 11 of the assembly and the inner face of recess 18. By this arrangement, as the embossing pressure and deformation 4 of the assembly increase, there ensues a point at which the plastic layer 11 ruptures and contracts to completely perforate the said film 11 in the embossed region but without perforating any of the remaining layers 10, 12 or 13 of the assembly. The net result is as shown in FiG. 2 in that the embossment 19 of the layer 10 completely protrudes through the ruptured plastic film 11 and because of the high elasticity of that film, it does not fracture or disintegrate during the embossing operation but merely contracts to the base of the embossment 19.

As shown in the diagram of FIG. 6, the film 11 is represented by a single thickness line and the adhesive force between the film 11 and the sheet 10 is indicated by the dotted arrow 20 which is normal to the flat or planar surface of the film 11. During the initial stages of the embossing pressure there is a slight tensile force represented by the arrow 21 which is at a slight angle to the plane of the film 11. At this point, the adhesive force 20 is much greater than the said tensile force. However, as the embossing pressure is increased, the tensile force 21, as indicated in FIG. 7, becomes greater than the adhesive force 20. Consequently, at the point where the elastic limit of the film 11 is reached, that film becomes completely ruptured and the film contracts by reason of the tensile force 21 to the base of the embossment. It should be observed that it does not contract any further because the flat unembossed areas of the film 11 are rigidly clamped between the cooperating edges of the two die members as indicated in FIG. 8.

Since the sheet 10 is of such material that it remains permanently deformed after the embossment, and since it is transparent or at least translucent, the color of the adhesive 12 is visible only through the raised embossed portions 19 of the sheet 10. Therefore, if the adhesive 12 is of a different color than the film 11, the embossments will appear as of the same color as the adhesive 12 and will be in sharp contrast to the color of the film 11.

FIG. 4 shows a modification of FIG. l wherein the above described colored plastic film 11 instead of being coated on to a transparent embossable sheet 10,is coated on to an opaque sheet 22 whose color is different from the color of the film 11. The sheet 22 may be of paper, cardboard, lm, `metal o1' opaque plastic. In this embodiment, therefore, the adhesive 23 can be any well known uncolored or clear adhesive. When such an assembly is embossed, as above described, the film 11 becomes completely ruptured at the embossed areas and the permanent deformed embossments of the sheet 22 protrude therethrough to produce the desired contrasting embossment in the assembly.

FIG. 5 shows a modification of FIG. 4 wherein the opaque contrasting sheet or film 22, which is to be permanently deformed by embossment, is provided on its upper surface with a primer coat 24 before coating the plastic film 11 on to the assembly.

The primer coat 24 can be prepared and coated from aqueous solutions of polyvinyl alcohol, hydroxy ethyl cellulose, carboxy methyl cellulose, methyl cellulose, algin, sodium polyacrylates, etc. Solventecarried butyral or styrene resins can similarly be employed.

By using such a primer coat, a more accurate control of the relative differences in the forces 20 and 21 as hereinabove described (see FIGS. 6 and 7) can be provided. From the foregoing it will lbe seen that it is possible to produce an embossed strip or web with any desired contrast between the embossed and unembossed areas, and the embossed areas are very sharply defined because the film 11, by reason of its high plasticity and elasticity, does not become fragmented or broken into minute pieces during the embossing operation and therefore does not require any special treatment to remove such fragmented pieces and avoids the clogging of the embossing mechanism which might otherwise result from the presence of any such fragmented pieces.

While certain embodiments have been described herein, it will be understood that various changes and modifications may be made therein within the scope of the invention. The invention is not necessarily limited to an embossable assembly including the adhesive and strippable backing 13. For example, in the embodiment of FIG. 1 the assembly to be embossed may consist solely of the layers 10 and 11, and the adhesive 12 and backing 13 may be later applied if required. Likewise in the embodiments of FIGS. 4 and 5, if desired the elements 13 and 23 can be omitted. In fact, an embossable web can be formed entirely within the elements 10 and 11 of FIG. 1 since the element 10, being transparent or at least translucent, may be attached in any suitable manner to a receiving surface whose color contrasts with the color of the lm 11. Likewise, if desired, the primer coat such as coat 24 may be provided between the elements 10 and 11 of FIG. 1, and between the elements 11 and 22 of FIG. 4.

The expression rupture point, as employed herein, nieans the stress intensity required to rupture a sheet of material.

One of the advantages of the embossable web, according to the invention, is that it can be made suiciently thin and pliable to be reeled, and furthermore when it is used, it can be bent around sharp Icorners and the like without the danger of the embossed web producing undesirable marks at the corner regions where no embossments occur. This advantage results from the high elasticity of the lm 11 which enables it to be Ibent at a sharp angle without crazing or the like.

What is claimed is:

1. An embossable material comprising a base capable of cold ilow embossment to provide permanently offset embossed portions o n the upper surface thereof, a coating disposed in a plane overlying said surface of said base, said base having a rupture point substantially greater than the rupture point of said coating whereby said coating will rupture in the zone of said offset embossed portions, said coating being elastic up to its point of failure, said point of failure occurring at a predetermined point above,said plane, said coating having sufficient elasticity so that said coating ruptures without fragmentation, the elastic limit of said coating being substantially greater than" the elastic limit of said base, said coating having a color contrasting with the color of said base.

References Cited UNITED STATES PATENTS 3,047,443 7/ 1962 Anderson 156-219 2,243,736 5/ 1961 Loblein. 3,036,945 5/1962 SOuZa.

FOREIGN PATENTS 374,151 6/ 1932 Great Britain.

JACOB H. STEINBERG, Primary Examiner.

ROBERT F. BURNETT, Examiner. 

1. AN EMBOSSABLE MATERIAL COMPRISING A BASE CAPABLE OF COLD FLOW EMBOSSMENT TO PROVIDE PERMANENTLY OFFSET EMBOSSED PORTIONS ON THE UPPER SURFACE THEREOF, A COATING DISPOSED IN A PLKANE OVERLYING SAID SURFACE OF SAID BASE, SAID BASE HAVING A RUPTURE POINT SUBSTANTIALLY GEATER THAN THE RUPTURE IN THE ZONE OF SAID OFFSET EMBOSSED PORTIONS, SAID COATING BEING ELASTIC UP TO ITS POINT OF FAILURE, SAID POINT OF FAILURE OCCURING HAVING SUFFICIENT ELASTICITY SO THAT SAID COATING RUPTURES WITHOUT FRAGMENTATION, THE ELASTIC LIMIT OF SAID COATING BEING SUBSTANTIALLY GREATER THAN THE ELASTIC LIMIT OF SAID BASE, SAID COATING HAVING A COLOR CONTRASTING WITH THE COLOR OF SAID BASE. 